Mining machine



June 1, 1943.

A. F. LEHMAN N MINING MACHINE Filed Jan. 18, 1941 3 Sheets-Sheet 'l flzzeri BY ATTQRN NVENTOR F1 e& 277422.

June 1, 1943. v A. F. LEHMANN 2,320,874

MINING MACHINE 4 Filed Jan. 18, 1941' 5 Sheets-Sheet 2 INVENTOR filieri F1 ail/I n.

fiildi' 14a.

' ATTOR 5.

June 1, 1943. A. F. LEHMANN 2,320,874

MINING MACHINE Filed Jan. 18, 1941 3 Sheets-Sheet 3 INVENTOR E E Fxefimarziz ATTORNS? high.

Patented June I 19 MININGMA CHINE Albert F. Lehmann, Detroit, Mich, .assignor to. Hydraulic Machinery, Inc., Detroit, Mich a corporation of Michigan Application-January 18, 1941, Serial No. 374,98!

6 Claims. (01. 255-45) The present invention relates to mining ma chines and particularly relates to improvements in rotary drills for forming blast holes.

One of the primary objects of the present invention is to provide a machine of the type mentioned' in which the blast holes may be more quickly formed than by the implements now in Another object of the invention is to provide an hydraulically operated rotary mining drill which is functionally flexible so that it is readily accommodated to use on materials of different characteristics, such as .hard or soft materials.

Another object of the invention is to provide" a machine of the type mentioned which may automatically respond to variations in the hardness of the material worked upon so that when working on a soft spot the infeed of the drill is faster than when encountered by relatively hard material, whenthe infeed is slower.

Another object of the invention is to provide an improved drill of the type mentioned in which the rotary speed of the drill may be adjustably varied and in which the infeed of the drill may also be adjustably varied and may be set at a predetermined amount so that when the resistance to such infeed exceeds a certain amount, the infeed is stopped but the rotation of the drill continues.

A further object of the invention is to provide a drill of the type mentioned which may be operated so that the rate of infeed of the drill is adjustable and may be set so that the rate of infeed "is constant regardless of the resistance on the drill bit, or may be set so that the rate of infeed automatically varies in direct response to the amount of resistance to infeed of the material being worked upon so that if less resistance is encountered, the rate of infeed increases, and if greater. resistance is encountered, the rate of infeed decreases.

Another objectof the invention is to provide a drill of the type mentioned in which a quick return of the drill to its outer position is accomplished regardless ofthe rate of infeed.

Another object of the invention is to provide a drill of the type mentioned which is so constructed that the life of the drill bit is relatively Other objects of theinvention will become apparent from thefollowing specification, from the drawings relating thereto, and from the claims hereinafter set forth.

used to designate like parts in the several views throughout: o Figure l is a broken, side elevational view of a rotary mining drill unit embodying features of the present invention;

Fig. 2 is a top plan view with a portion broken away and illustrating a portion in cross-section of the construction shown in Fig. 1;

Fig. 3 is an elevational and cross-sectional view taken substantiallyalong the line 3-3 of Fig. 2;

Fig. 4 is an elevational and cross-sectional view taken substantially along the line 4-4 of Fig. 1;

Fig.5 isan elevational and cross-sectional view .taken substantially along the line 55 of Fig. 1;

Fig. 6 is an end elevational view taken substantially along the line 6-6 of Fig. 2;

Fig. 7 is a diagrammatic view illustrating the drill unit of the present invention set up for use in a mine; and

Fig. 8 is a diagrammatic view illustrating the hydraulic circuit and'the functional relationship of certain of the elements of the construction of the present invention.

In general, the present invention is directed to a rotating drill for drilling blast holes in mining operations. Such construction consists of an hydraulic power plant and an hydraulic drill unit. The power plant includes an oil reservoir, an electric motor, an hydraulic pump ,connected to the hydraulic motor, a safety valve for the pump and flexible pressure and return lines leading to and from the drill unit. The power plant may be mounted in a suitable location with the lines or conduits leading to the drill unit, which may be located in the mine where the drilling is to take place.

The drill unit is of a compact nature and may be suitably mounted on standards disposed within the mine so that the drill may be disposed to face the wall where the drilling is to take place. The drill unit includes an-elongated standard, which is adjustable with respect to the wall and which has a rotating drill and spindle movably mounted thereon. The means for rotating the drill comprises an hydraulic motor and the drill is movable toward and from the wall during rotation by hydraulically actuated means in the form of a cylinder and piston construction. Controls are provided in the hydraulic circuit and the fluid motor is adjustable so that the drill is controllably fed into the work under controlled rotative speed. r

The machine may be operated so that up to a In the drawin s, in which like numerals are predetermined pressure within the feed cylinders,

feed automatically decreases. Also. the circuit includes pressure regulating means of such a nature that when the. pressure within the feed cylinders builds up beyond a predetermined amount, the fluid supplied such cylinders is diverted therefrom and is returned to the tank, so that the infeed is cut off while the drill bit continues to rotate. 7

Referring to the drawings for a detailed description of one illustrative embodiment of the present invention, and referring particularly to Figs. 1 through 6, in which the drilling unit is disclosed, such drilling unit includes an elongated base or standard I II, having a finished upper surface i2 and having ways ill formed in the sides thereof. A housing I 8 is slidably disposed on the finished surface i2 of the standard III for sliding The pressure of the water within chamber- 4| serves to force the seals ll walls to further aid in the sealing.

The drive shaft SI extends longitudinally of the housing It and is rotatably mounted thereon by means of ball bearing assemblies II disposed adiacent the forward and rear ends of such drive shaft. 'Av spacer sleeve It embraces the drive shaft 20 and abuts against the ends of the. inner racers .of the facing bearing assemblies II to retain such bearing assemblies in place. An annular'member to (Fig. 5) is fixedly secured to the j housing It and has a shoulder portion which v longitudinal displacement.

movement therealong. Such housing It has depending side portions it, each of which has rollers 20 mounted thereon. Such rollers 20 are so disposed that they are received within the ways ll for guiding the housing and associated elements as they move along standard III.

A hollow spindle 22 is rotatably mounted on housing It by means including a spindle nose element 24, having a'tapped central opening 26 which threadably receives therein the threaded end of spindle 22. The mounting member is connected to a complementary mounting element 28 for rotation therewith by means of tongue. and groove connections 30, as shown in Fig. 1. Vulcanized rubber 22 'is disposed' between thev facing surfaces of members 24 and 22 and is vulcanized to such surfaces so as to provide a cushion for .the spindle nose. The member 24 also has an inwardly directed tubular portion 84 which engages the inner surface of member 28, sothat a, rugged spindle nose is provided.

The member 28- is secured to a tubular drive shaft 36, which is disposed within the bore of housing It, by means of screws 38 or the like.

-The front closure plate of housing It is formed bears against the outer I race of the outer bearing assembly I! to hold such assemblies against A suitable annular seal 82 may be held in. wardly projecting shoulder of member I.

The inner end 01 the drive shaft ll may be closed and may be of slightly reduced diameter as indicated at It in Hg. 5, for connection to the drive means which will be described in detail hereinafter.

The drive means for the shaft 38 and, there- 7 fore, for the spindle 22 and drill bit II, comprises a standard fluid or hydraulic motor to which is here illustrated as being of the piston type, but

which may also be of the vane, gear or rotor types. Such piston motor 88 includes the usual hand wheel 68 which is operatively connected to. the piston elements of the motor for varying the angular positions thereof in order to control the angular relation of the piston motor elements.

with an annular chamber 40 adjacent the spindle Y nose, which communicates with the interior of the tubular shaft 36 through a plurality of annular spaced radially'disposed openings 42, and which in turn communicates with the interior of the hollow spindle 22 through the hollow member 24. Annular, rubber sealing elements 44 are disposed within the chamber 40 and are urged against the opposite walls thereof by means of compression springs I, which have their ends disposed within metal cup elements 48, which in turn bear against the seals 44. An annular. closure ring is fixed to the front face of the closure plate by means ofv screws 52 or the like, and bears against one surface of the outermost sealing element 4|. The-inner edge of sealing element 44 bears against a radial shoulder 82 formed on the drive shaft 2|. Water from a suitable source is conducted-into the chamber 49 through an opening 54' formed in the front closure plate of the housing and flows through the spindle 22 and out through the drill bit 54,- which is removably secured to the forwardmost end of the spindle 22, so that the water is directed against the material being worked upon through the hollow bit 54. The bit 54 is formed of suitable material such ascarborundum or the like.

In such motors, the greater the angular relationship, the greater the displacement and the less the speed, and, conversely, the less the angular relationship, the less the displacement and the greater the speed. As the speed decreases, the torque increases. The motor 6! is, of course, provided with the usual inlet and outlet ports and the relationship .of such ports will be described in connection with the description of Fig. 8..

The housing of motor II is secured to a plate member "In, see Figs. 3 and 5, which in turn is secured to the rear face of housing ll by suitable means, such as screws 12.

The motor 66 has the usual drive shaft 14 associated therewith to which a pinion II is fixed for rotation therewith. Such pinion I6 is constructed and arranged to mesh with the teeth of an internal gear It, so that upon rotation of the pinion 18 the gear II is correspondingly driven. The gear 18 has an integral hub portion 8| which embraces the inner reduced end '4 of drive shaft 36 and is keyed thereto by means of a suitable key 82. A threaded end element It is threadably received over the inwardly projecting threaded end of reduced portion 84. Such member 24 projects radially outwardly so that it bears against the inner face of hub portion II, and may be fixed against rotation by means'of a suitable set screw 88, which is so arranged that a portion of the head of such screw is received within a slot 88 formed in member I4. It will thus be seen that the shaft It is rotatably mounted within housing It and is secured to the internal gear 18 for rotation thefewith/ It will further be appreciated that as fluid .under pressure is supplied to the fiuid motor I, the drill bit I is rotated of spindle 22 with the through the connections driving pinion ll, above described. Means are provided for sliding the housing ll along the standard It so that the drill I4 is fed inwardly of and away from the work. Such means includes a pair of cylinders 90 having their fora ainst their adjacent place by a radially in-,

ward ends received-within cylindrical portions 82 formed in the housing I8 at opposite sides thereof. The forwardmost ends of the cylinders are closed by thejhousin'g end plate 84, and Y the rear ends have caps 86 secured thereto. A piston 88 is disposed within each of such cylinders andhas a piston rod 88 associated therewith which projects throughthe cap 86 of each of the cylinders. The rearmost ends of the piston rods 08 are fixed to the standard I bymeans of a transversely extending member IOI. Such member MI is secured to the standard I0 and the piston rods 68 are secured to such member IM so that when fluid under pressure is supplied the forwardmost end of the cylinders 90, the housing I8 is caused to slide forwardly of the standard I0 to feed the drill inwardly. When fluid is supplied the opposite ends of cylinders 90, the housingI6, together with the drill, is backed oil to move the drill outwardly from the work; While the inlet and outlet ports of such cylinders are not shown here, they are, however, shown in Fig. 8, and will be described in connection there- -with. vI I A four-way valve I02 is mounted on the housing of the fluid motor 66 by means of a bracket I04. Such four-way valve has an inlet conduit I06 which communicates with a central opening in the valve housing and also has a return conduit I08 which communicates with the interior of the valve through a central opening disposed substantially at a right angle to the opening for the conduit I06.- A conduit! I0 leads to the forward ends of cylinders 80 for feeding the drill inwardly, and a conduit II 2 leads to and communicates with the rear ends of the cylinders 00 for backing the drill outwardly from the work.

The details of the hydraulic circuit will be described later, in connection with the description of Fig. 8.

The spindle 22 is of substantial length so that a hole of considerable depth may be drilled. In order to support the forward end of the spindle at the beginning of the drilling operation, a steady rest generally indicated at H4 is mounted on the forward end of the standard I0. Such steady rest may be of suitable construction, and is here v illustrated as being of separable half sections II6 which, when upright, provide an aperture for slidably receiving therein the spindle 22. The sections II6 are pivotally mounted upon a suitable pivot pin Ill and, while such sections may fall apart to free the spindle 22 of any support,

they are releasably held together by means of a pair of upstanding arms II8 which are secured to a transversely extending pivot pin I20. When the arms are in their upper position, as shown; the sections II6 are held together, while when the arms 8 are pivoted to drop away from enare released from engagementwith the arms I I8, if desired.

Referring to Fig. 7, the drill unit is diagrammatically illustrated in position within a mine, and such unit may be mounted to an upright post 424, which is disposed within the mine, by means of a laterally extending arm I26 havinga clamping portion I28 which embraces the post I24 and may be adjustably, fixed thereto at the desired height. I Another upstanding mounting arm I30 is mounted on the arm I26 by means of a slidable clamp I32 so that the arm 130 may be adjustably fixed with respect to the arm I26. The arm I30 is provided with a guideway I34, having upwardly tapered side walls, which receives therein a complementary member I36. Such member I36 is secured to the under side of the standard I0, and may be elongated in form in order to provide for rough adjustments tlagnthe standard I0 along the. supporting bracket It will thus be seen that the drill unit may be conveniently mounted upon the arm I80 and roughly positioned within the mine at the desired location. Thereafter, the drill may be rotated and reciprocated to provide the in and out feeds for drilling the blast holes.

Referring to Fig. 8, the hydraulic power plant and hydraulic drill unit are diagrammatically illustrated together with the hydraulic circuit therefor. The power plant includes an oil tank or reservoir I40, which may be mounted on skids for movement within the mine. A double end electric motor I42 is mounted on the tank I40, and. has oppositely directed drive shafts lines in the usual way.

The pump I44 is of standard construction and may be of the gear, vane, or other suitable type, as will be appreciated by those skilled in the art. An inlet conduit I46 communicates with the oil in tank I40 and also communicates with the inlet of the pump I44. An outlet conduit I48 leads from the discharge side of the pump I44 and communicates with a safety relief valve I50, which is of conventional construction. A

return'line I52 leads from the relief valve back to conduit I54, which returns to the tank so that the pump I44 may be continuously operated when the drill unit is shut off, and the oil recirculated back into the tank. A conduit I56 leads from the relief valve I50 and has a shutoffvalve I58 interposed therein. A flexible conduit I60 is connected to the conduit I56 and leads to the hydraulic drill unit. Such conduit #60 communicates with a rigid conduit "I62 mounted on the drill unit,

' An inlet conduit I64 communicates with con.- duit I62 and leads to the inlet of the fluid motor 66. An outlet conduit I66 communicates with the discharge of the motor 66 and come and such rod is so positioned that as the housing I6 moves forward, the forward end of the rod abuts against one of the upstanding arms H8 to pivot both or the arms II8 out of engagement with sections II6 so that such sections fall away from the spindle. Suitable spring means may be provided forseparating the sections when they municates with another conduit I68. Such conduit I68 may be placed in communication with the conduit I62 or may be shut off from such communication by means of a shut-oft valve I10. When such valve is shut oil, the fluid under pressure passing through conduit I62, passes through the motor 66, causing rotation of the The arrangement for only one end spindle 22, and then passes into the conduit I68 through conduit I66. when the valve I is open, the fluid passes directly from conduit I62 into conduit I88. Y

Conduit I68 communicates with the inlet of a conventional pressure regulating valve I12, and one of the outletsof such valve communicates with the inlet conduit I06 of four-way,

valve I 02. Another of the outlets oi the valve I12 communicates with a return conduit I14 which, in turn, communicates with the return line I08 of the four-way valve I02. A ressure gauge I16 is interposed between the valve I12 and the four-way valve I02 to indicate the pressure in the inlet line I06;

As stated, the pressure regulating valve I12 is of conventional construction and is adjustable so that ,it is responsive to variable pressures.

depending upon the adjustment of the valve. In operation, there is free flow of fluid from conduit I68 to conduit I06, but in the event that the pressure builds up in conduit I06, the plunger f valve I 12 is actuated to open the port leading to conduit I14 sothat fiuidis diverted from flow into conduit I06 and is returned through conduit I14 to the return line I08, around four-way valve I02,

The four-way valve I02 has an operating plunger or spool I16 mounted therein which is operated by a handle I18 so that the valve may be positioned to communicate the inlet I06 with the conduit 'I I0, in the position shown in Fig. 8. The conduit H2 is then in communication with the return line I08 through the inset portion I80 of the spool I16. The opposite end of the spool has a similar inset portion I82, so that when the valve is shifted to such a position that the conduit I06 is in communication with conduit II2, the conduit IIO then returns the fluid through the inset portion I82 into line I08.

the valve m m the position shown, the drill bit a 64 is fed inwardly, as mentioned .above. Withconduits I08, I94, I" and "4.. with this setting,

With the valve in the position shown, the fluid under pressure enters the forward ends of cylinders 90 which communicate directly with conduit H0. The cylinders 90 are then caused tomove forwardly, moving therewith the spindle 22 and drill bit 54 to cause the infeed of the drill.

The rear ends of the cylinders 90 communicate through branch conduits I86 with conduit H2. The conduit II2 has a by-pass conduit I88 communicating therewith, and an adjustable needle valve I90 is interposed in such conduit II2 between the points at which the conduit I88 communicates therewith. A check valve I92 01 conventional construction is interposed in the conduit I80 and permits free flow through such conduit in the direction of the arrow, but prevents flow in the opposite direction.

The return line I08 is in communication with a flexible return conduit I94, which, in turn, communicates with a rigid'conduit I96 mounted on the power plant. A shut-off valve I98 is interposed in the conduit I96. A return conduit I96 communicates with conduit I54 for return to the tank.

It will thus be seen that with the valves I58 and I98 shut off, there is no flow oi the fluid under pressure to the drill unit and the flexible conduits I60 and I94 may be disconnected, if desired. However, with the valves I58 and I98 open and the valve I10 closed, fluid under pressure passes through the hydraulic motor 66 to drive the same and to rotate the spindle 22. The speed of the spindle 22 and drill bit 54 may be controlled by adjusting the hand wheel 68. With the rate of the infeed automatically -varies in that in the event that the drill strikes a soft spot the resistance to its infeed decreases and its rate of inl'eed increases. Conversely, when a hard spot is struck, the rate of infeed will decrease. By adjusting the needle valve I to restrict the flow through conduit II2, the rate of infeed will be constant for a particular setting in that the restricted discharge from the cylinders 80 will determinesuch rate of infeed.

In the event that the resistance to the infeed increases to a predetermined amount, depending upon the setting of valve I12, such valve I12 will act to by-pass a portion of, or all of, the'fiuid from conduit I06 into conduit I14, and return such fluid to the tank, so that the infeed is either reduced or entirely out ch.

By shifting the spool I16 so that the conduit I06 communicates with conduit H2, and conduit- IIO communicates with conduit I08, the drill is backed out or returned to its outward position. A quick return is provided regardless of the restriction imposed by the setting of needle valve I in that the one-way valve I82 permits unrestricted flow through conduit I88 in the direction of the arrow of such valve. The return of the fluid from cylinders 90 is through conduits II0 and I08.'

It will thus be appreciated that by setting the various valves described above in desired positions, that the construction of the present invention provides a functionally flexible apparatus.

.Such apparatus is, therefore, adapted to meet the different conditions that are found in mining operations so that best results may be obtained.

Formal changes may be made in the specific embodiment of the invention described without departing from the spirit and substance of the invention, the scope with the appended claims.

What'is claimed is: I

l. A rotary drilling machine comprising a drill,

a first hydraulically actuated means for rotating said drill, a second hydraulically actuated means for feeding said drill inwardly and outwardly,

common means forming an hydraulical circuit for supplying fluid under pressure to both of said first and second means, means interposed insaid circuit between said first and second means to regulate the fiow'of fluid to said second means depending upon the pressure within said second means, a reversing valve to control the flow of fluid to said second means, and restricting means interposed in said circuit for controlling the flow of fluid through said second named means.

2. A rotary drilling machine comprising a drill, aflrst hydraulically actuated means for rotating said drill, a second hydraulically actuated .means for feeding said drill inwardly and outwardly, common means forming an hydraulical circuit for supplying fluid under pressure to both of said first and second means, means interposed in, said circuit between said first and second means to regulate the flow of fluid to said second means depending upon the pressure within said second means, a reversing'valve to control the flow of liquid to said second means, and restrict of which is commensurate.

ing means interposed in said circuit on the discharge side of said second means for controlling the flow of fluid through said circuit to regulate the rate of infeed of said second means.

3. A rotary drilling machine comprising a drill, a first hydraulically actuated means for rotating said drill, a second hydraulically actuated means for feeding said drill inwardly and out, wardly, common means forming an hydraulical circuit for supplying fluid under pressure to both of said first and second means, means interposed in said circuit between said first and second means to regulate the flow of fluid to said second means depending upon the pressure within said second means, a reversing valve to control the flow of fluid to said second means, and restricting means interposed in said circuit on the discharge side of said second means for controlling the volume of fluid discharged therefrom to thereby regulate the rate of infeed of said second means.

4. A rotary drilling machine comprising a drill, a variable speed hydraulically actuated means for rotating said drill, an hydraulically actuated means for feeding said drill inwardly and outwardly, common means forming an hydraulic circuit for supplying fluid under, pressure to both of said first and second named means, means interposed in said circuit on the inlet side of said second named means to divert the flow of fluid interposed in said circuit on the discharge side of said second named means for regulating the rate of infeed of said second named means.

5. A rotary drilling machine comprising a drill, a first hydraulically actuated means for rotating said drill at variable speeds, a second hy draulically actuated means for feeding said drill inwardly and outwardly, common means forming an hydraulic circuit for supplying fluid under pressure to both of said first and second means in series, means interposed in said circuit between said first and second means to regulate the flow of fluid to said second means depending only upon the pressure within the said second means, a reversing valve to control the flow of fluid to said second means and restricting means interposed in said circuit for controlling the flow of fluid through said second named means.

6. A rotary drilling machine comprising a drill,

' a first hydraulically actuated means for rotating said drill at variable speeds, a second hydraulically actuated means for feeding said drill inwardly and outwardly, common means forming an hydraulic circuit for supplying fluid under pressure to both of said first and second means in series, means interposed in said circuit to regulate the ,flow of fluid to said second means depending upon the pressure within said second means and independent of the speed of rotation of said drill, a reversing valve to control the flow of fluid to said second means, and restricting means interposed in said circuit for controlling the flow of fluid through said second named means.

ALBERT F. LEBMANN.

CERTIFICATE OF CORRECTION. Patent No. 2,52o,e7h.' June 1, 191m.

1 ALBERT F. IEHMANN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction es followei Page 13., sec- 0nd column, line 75, claim 2, for "liquid" read "fluidand that the said Letters Patent should be read with this correction therein thet'the {same may conform to the record of the case in the Patent Office.

Signed. and sealed this 6th day of July, A. 1). 19h

- Henry Van Aradale, (Seal) Acting Commissioner of Patents. 

